South Shore 3 Beach Minimum Half Marathon

From there, the course heads south and east along Nantasket Avenue before turning left onto Jerusalem Road, an exclusive area known for its stately mansions that sit atop big green lawns overlooking the rocky shoreline of the beaches below.
This continues for about 2 miles, and then the road becomes Atlantic Avenue, which unfolds past Black Rock Beach, Pleasant Beach and Sandy Beach.
Miles 4 and 5 bring runners into Cohasset, another beautiful small seaside town (population about 7,500) that’s located roughly where Boston Harbor ends and Massachusetts Bay begins.
The course curls around the edges of Cohasset Cove and brings runners over the bridge at Government Island, and then begins a quiet stretch through shaded, residential areas, to the turnaround loop that circles around Trysting Road and Indian Trail.
After that, runners make the loop and then retrace their steps all the way back to Hull and Nantasket Beach, getting a chance to see everything they’ve just seen a second time. Runners must finish the race within the 3-hour time limit — which organizers say means that the race is for runners only, no walkers.